64 research outputs found

    A powerful visualization technique for electricity supply and demand at industrial sites with combined heat and power and wind generation

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    The combination of wind generation and combined heat and power (CHP) on an industrial site brings significant design and operational challenges. The stochastic nature of wind power affects the flows of electricity imported and exported to and from the site. Economies of scale favor larger wind turbines, but at the same time it is also desirable to minimize the amount of electricity exported from the site to avoid incurring increased network infrastructure usage charges. Therefore the optimum situation is to maximize the proportion of the site load served by on-site generation. This paper looks at a visualization technique for power flows on an industrial site, which can be used to size on-site generators. The technique is applied to a test case, demonstrating how a simple combined heat and power control scheme can support the integration of on-site wind power. The addition of such CHP control has a small impact on the CHP unit but can greatly increase the proportion of wind generation consumed on-site. This visualization technique allows the comparison of different generation mixes and control schemes in order to arrive at the optimal mix from a technical and economic viewpoint

    Developing farm-level sustainability indicators for Ireland using the Teagasc National Farm Survey

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    peer-reviewedIn the context of an expanding, export-dependent agri-food sector, indicators of sustainable development and intensification are necessary to measure, assess and verify the comparative advantage afforded by Ireland’s natural pastoral-based food production systems. Such indicators are also necessary to ensure that we produce more food with less adverse impacts on the Irish environment, climate and society. This article outlines the development of farm-level indicators that refect the multifaceted nature of sustainability, which is encompassed in economic, environmental and social indicators. The role of innovation in farm sustainability was also examined. A comparison of indicators across Irish farm systems showed that dairy farms, followed by tillage farms, tended to be the most economically and socially sustainable farm systems. In relation to greenhouse gas emissions in particular, the top-performing dairy farms, in an economic sense, also tended to be the best-performing farms from an environmental sustainability perspective. This trend was also evident in relation to the adoption of innovative practices on farm, which was found to be strongly correlated with economic performance

    Factors associated with profitability in pasture-based systems of milk production

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    peer-reviewedThe global dairy industry needs to reappraise the systems of milk production that are operated at farm level with specific focus on enhancing technical efficiency and competitiveness of the sector. The objective of this study was to quantify the factors associated with costs of production, profitability, and pasture use, and the effects of pasture use on financial performance of dairy farms using an internationally recognized representative database over an 8-yr period (2008 to 2015) on pasture-based systems. To examine the associated effects of several farm system and management variables on specific performance measures, a series of multiple regression models were developed. Factors evaluated included pasture use [kg of dry matter/ha and stocking rate (livestock units/ha)], grazing season length, breeding season length, milk recording, herd size, dairy farm size (ha), farmer age, discussion group membership, proportion of purchased feed, protein %, fat %, kg of milk fat and protein per cow, kg of milk fat and protein per hectare, and capital investment in machinery, livestock, and buildings. Multiple regression analysis demonstrated costs of production per hectare differed by year, geographical location, soil type, level of pasture use, proportion of purchased feed, protein %, kg of fat and protein per cow, dairy farm size, breeding season length, and capital investment in machinery, livestock, and buildings per cow. The results of the analysis revealed that farm net profit per hectare was associated with pasture use per hectare, year, location, soil type, grazing season length, proportion of purchased feed, protein %, kg of fat and protein per cow, dairy farm size, and capital investment in machinery and buildings per cow. Pasture use per hectare was associated with year, location, soil type, stocking rate, dairy farm size, fat %, protein %, kg of fat and protein per cow, farmer age, capital investment in machinery and buildings per cow, breeding season length, and discussion group membership. On average, over the 8-yr period, each additional tonne of pasture dry matter used increased gross profit by €278 and net profit by €173 on dairy farms. Conversely, a 10% increase in the proportion of purchased feed in the diet resulted in a reduction in net profit per hectare by €97 and net profit by €207 per tonne of fat and protein. Results from this study, albeit in a quota limited environment, have demonstrated that the profitability of pasture-based dairy systems is significantly associated with the proportion of pasture used at the farm level, being cognizant of the levels of purchased feed

    Wisconsin’s Environmental Public Health Tracking Network: Information Systems Design for Childhood Cancer Surveillance

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    In this article we describe the development of an information system for environmental childhood cancer surveillance. The Wisconsin Cancer Registry annually receives more than 25,000 incident case reports. Approximately 269 cases per year involve children. Over time, there has been considerable community interest in understanding the role the environment plays as a cause of these cancer cases. Wisconsin’s Public Health Information Network (WI-PHIN) is a robust web portal integrating both Health Alert Network and National Electronic Disease Surveillance System components. WI-PHIN is the information technology platform for all public health surveillance programs. Functions include the secure, automated exchange of cancer case data between public health–based and hospital-based cancer registrars; web-based supplemental data entry for environmental exposure confirmation and hypothesis testing; automated data analysis, visualization, and exposure–outcome record linkage; directories of public health and clinical personnel for role-based access control of sensitive surveillance information; public health information dissemination and alerting; and information technology security and critical infrastructure protection. For hypothesis generation, cancer case data are sent electronically to WI-PHIN and populate the integrated data repository. Environmental data are linked and the exposure–disease relationships are explored using statistical tools for ecologic exposure risk assessment. For hypothesis testing, case–control interviews collect exposure histories, including parental employment and residential histories. This information technology approach can thus serve as the basis for building a comprehensive system to assess environmental cancer etiology

    The Sustainable Intensification of the Irish Dairy Sector

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    peer-reviewedThe concept of sustainability is one of the forefront issues in global agricultural production at present, given mounting pressure to increase food production in both a socially responsible and environmentally friendly way. From an Irish perspective the sustainable intensification of agriculture is of particular relevance given ambitious targets to increase milk production by 50 percent by 2020, in the context of European milk quota removal. Alongside this, environmental targets may be specified, meaning that expansion would have to be achieved in a sustainable way. To evaluate dairy farm-level sustainability a series of indicators are developed here using Teagasc National Farm Survey FADN (Farm Accountancy Data Network) data for Ireland from 2012. Three dimensions, reflecting the multifaceted nature of sustainability (economic, environmental and social) are considered. Given the environmental challenges inherent in the sustainable intensification of agriculture, it is encouraging to observe that the more intensive, top performing farms (in an economic sense) emit relatively less greenhouse gases when compared to their less intensive counterparts. Conversely, the better performing farms in economic terms tend to have higher nitrogen surplus per hectare on average. This is consistent with their higher rates of production intensity but poses a challenge in terms of sustainable expansion. That said this analysis demonstrates that the nitrogen use efficiency of milk production is positively correlated with economic performance, with more intensive farms producing relatively more milk per kg of nitrogen surplus. From a social perspective demography also tends to be correlated with economic performance. These indicators allow for the continued assessment of the sustainability status of Irish farming

    Increased mitochondrial DNA diversity in ancient Columbia River basin Chinook salmon Oncorhynchus tshawytscha

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    The Columbia River and its tributaries provide essential spawning and rearing habitat for many salmonid species, including Chinook salmon (Oncorhynchus tshawytscha). Chinook salmon were historically abundant throughout the basin and Native Americans in the region relied heavily on these fish for thousands of years. Following the arrival of Europeans in the 1800s, salmon in the basin experienced broad declines linked to overfishing, water diversion projects, habitat destruction, connectivity reduction, introgression with hatchery-origin fish, and hydropower development. Despite historical abundance, many native salmonids are now at risk of extinction. Research and management related to Chinook salmon is usually explored under what are termed “the four H’s”: habitat, harvest, hatcheries, and hydropower; here we explore a fifth H, history. Patterns of prehistoric and contemporary mitochondrial DNA variation from Chinook salmon were analyzed to characterize and compare population genetic diversity prior to recent alterations and, thus, elucidate a deeper history for this species. A total of 346 ancient and 366 contemporary samples were processed during this study. Species was determined for 130 of the ancient samples and control region haplotypes of 84 of these were sequenced. Diversity estimates from these 84 ancient Chinook salmon were compared to 379 contemporary samples. Our analysis provides the first direct measure of reduced genetic diversity for Chinook salmon from the ancient to the contemporary period, as measured both in direct loss of mitochondrial haplotypes and reductions in haplotype and nucleotide diversity. However, these losses do not appear equal across the basin, with higher losses of diversity in the mid-Columbia than in the Snake subbasin. The results are unexpected, as the two groups were predicted to share a common history as parts of the larger Columbia River Basin, and instead indicate that Chinook salmon in these subbasins may have divergent demographic histories.Ye
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